"It was a pattern of life where you could tell things were not going well for Tom", Slater said, referring to Hodgkinson by his middle name.
Hodgkinson had expressed anti-Republican views online but Slater said, "There were no threats whatsoever".
"In April 2017, the shooter rented a storage unit in Alexandria", Slater said, "in which we found a laptop computer, an excess of 20o rounds of ammunition, a receipt for a November, 2016 gun purchase, and additional SKS rifle components".
Mr Scalise and other congressional Republicans were practising for their annual charity baseball game against Democrats when a gunman started shooting. He has undergone several surgeries and remains hospitalized.
But Carter also gave the services until July 1 to develop policies to allow people already identifying as transgender to newly join the military, if they meet physical, medical, and other standards and have been stable in their identified genders for 18 months.
The investigation into the attack is still active as police continue to analyze evidence from the scene, authorities said.
The unemployed former home inspector from Belleville, Illinois, was known to have anger management issues, was running out of money and on prescription medication before the attack, Slater said.
The 66-year-old gunman who opened fire one week ago on members of Congress at a Northern Virginia ball field had photographed Washington landmarks including the Library of Congress, the Supreme Court and the Capitol, the F.B.I. said Wednesday, but the agency did not believe those sites were targets. The gunman later died after he was shot by the police.
Scalise, who was shot in the hip, was at "imminent risk of death" when arrived at D.C. MedStar Washington Hospital Center, doctors said last week. Bernie Sanders' presidential campaign, railed against Republicans and President Donald Trump in social media posts.
On the morning of the shooting, Hodgkinson approached a witness near the baseball field, asking, "Is this the Republican or Democrat baseball team?"
Shortly after that parking lot encounter, according to the FBI, Hodgkinson went to his van, retrieved his rifle and donned a holstered 9 mm handgun.