Here's a complete list of all 7 rising juniors who ran a sub 10.5 time last year, followed by a breakdown by state.  If you're in a hurry, note that this would have been the fastest 100 for a 10th grader in every state last year except for DC, Kansas, Nevada, and Texas.  Unless he's one of these 7 (and basically the only possibilities are Wilson, Bell and Turner - and Bell isn't really a 10.4 guy unless he's got a serious tailwind), I'm pretty sure OP is exaggerating the kid's time/abilities

United States
Ashton Torns (Texas) 10.27 (w 5.7 mph tailwind) -> doesn't appear to play football
Nyckoles Harbor (DC) 10.31 -> high 4 star ATH with offers from Oregon, Penn St, Oklahoma etc.  He's 6'5", 225 though so not who OP is talking about
Zachariah Branch (Nevada) 10.33 -> high 4 star WR with offers from Alabama, USC etc.  He's 5'9", 185 though so not who OP is talking about
Jeremiah Smith (Kansas) 10.36 -> doesn't appear to play football at all
Demari Wilson (Texas) 10.38 -> no 247 or recruiting profile, but did upload some video of him playing WR to Hudl in Dec 2018, 2.5 years ago. Didn't play for his HS team last year, but might be this year?
Micah Bell (Texas) 10.46 (w 6.4 mph tailwind) -> listed as a CB, 5'11", 160 so could fit the profile; already has 14 offers from Florida, Michigan, Colorado etc.
Brice Turner (Texas) 10.49 -> no 247 or recruiting profile, but did upload some video of him playing WR to Hudl in Dec 2019.  Mostly sprinting out before his QB throws up a jump ball

Alabama
None (top 10th grade time was 10.74)

Alaska
None (top 10th grade time was 11.19)

Arizona
None (top 10th grade time was 10.76)

Arkansas
None (top 10th grade time was 11.09)

California
None (top 10th grade time was 10.55)
This was JeyQuan Smith with a 2.5 mph tailwind, but he does also play football and is listed as WR/CB

Colorado
None (top 10th grade time was 10.77)

Connecticut
None (top 10th grade time was 10.86)

Delaware
None (top 10th grade time was 10.68)

D.C.
Nyckoles Harbor 10.31 - high 4 star ATH with offers from Oregon, Penn St, Oklahoma etc.  He's 6'5", 225 though so not who OP is talking about
(next best 10th grade time was 10.98)

Florida
None (top 10th grade time was 10.66)

Georgia
None (top 10th grade time was 10.74)

Hawaii
None (top 10th grade time was 11.19)

Idaho
None (top 10th grade time was 10.90)

Illinois
None (top 10th grade time was 10.84)

Indiana
None (top 10th grade time was 10.72)

Iowa
None (top 10th grade time was 11.10)

Kansas
Jeremiah Smith 10.36 -> doesn't appear to play football at all
(next best 10th grade time was 10.74)

Kentucky
None (top 10th grade time was 10.95)

Louisiana
None (top 10th grade time was 10.63)

Maine
None (top 10th grade time was 11.11)

Maryland
None (top 10th grade time was 10.98)

Massachusetts
None (top 10th grade time was 11.08)

Michigan
None (top 10th grade time was 10.57)
This was Corey Royster, but he does also play football and is listed as WR

Minnesota
None (top 10th grade time was 11.05)

Massachusetts
None (top 10th grade time was 11.08)

Mississippi
None (top 10th grade time was 11.00)

Missouri
None (top 10th grade time was 10.63)

Montana
None (top 10th grade time was 11.14)

Nebraska
None (top 10th grade time was 10.94)

Nevada
Zachariah Branch 10.33 -> high 4 star WR with offers from Alabama, USC etc.  He's 5'9", 185 though so not who OP is talking about
(next best 10th grade time was 11.14)

New Hampshire
None (top 10th grade time was 11.49)

New Jersey
None (top 10th grade time was 10.86)

New Mexico
None (top 10th grade time was 10.82)

New York
None (top 10th grade time was 10.80)

North Carolina
None (top 10th grade time was 10.65)

North Dakota
None (top 10th grade time was 11.02)

Ohio
None (top 10th grade time was 10.65)

Oklahoma
None (top 10th grade time was 10.65)

Oregon
None (top 10th grade time was 11.07)

Pennsylvania
None (top 10th grade time was 10.71)

Rhode Island
None (top 10th grade time was 11.26)

South Carolina
None (top 10th grade time was 10.60)

South Dakota
None (top 10th grade time was 10.69)

Tennessee
None (top 10th grade time was 10.76)

Texas
-> Ashton Torns 10.27 (w 5.7 mph tailwind) -> doesn't appear to play football
-> Demari Wilson 10.38 -> no 247 or recruiting profile, but did upload some video of him playing WR to Hudl in Dec 2018, 2.5 years ago
-> Micah Bell 10.46 (w 6.4 mph tailwind) -> listed as a CB, 5'11", 160 so could fit the profile; already has 14 offers from Florida, Michigan, Colorado etc.
-> Brice Turner 10.49 -> no 247 or recruiting profile, but did upload some video of him playing WR to Hudl in Dec 2019.  Mostly sprinting out before his QB throws up a jump ball
(next best 10th grade time was 10.52 by Korey Mosley)

Utah
None (top 10th grade time was 10.67)

Vermont
None (top 10th grade time was 11.57)

Virginia
None (top 10th grade time was 10.83)

Washington
None (top 10th grade time was 10.61)

West Virginia
None (top 10th grade time was 11.09)

Wisconsin
None (top 10th grade time was 10.78)

Wyoming
None (top 10th grade time was 10.80)