Police still do not know Tineo's motive. Police said Tineo fired shots at a car with two students just off of the Willcox High School campus.
A 17-year-old high school freshman in the car was transported to Northern Cochise Community Hospital with non-life threatening injuries. Police said he was not shot but was injured by shards of glass.
A school employee, who witnessed Tineo firing at the car, yelled at the shooter. Tineo fired at the employee but police say the employee was not injured.
Police responded and arrested Tineo a block south of the scene shortly after the 3:15 p.m. 911 call.
Tineo is in the Willcox jail and was charged with three counts of attempted murder and many other charges.
The high school went into lockdown. Lownds said Willcox Elementary and Willcox Middle schools, which share the campus, also were locked down. The lockdown was lifted shortly after 5 p.m.
The shooting happened at the school's baseball field and those involved were there to see a game.
Roughly 330 students are enrolled at Willcox High School. The campus is home to a Cochise Community College satellite campus, which also was locked down.