A disgruntled former client apparently took out his anger over a patent case on the firm:
"The law offices where Friday’s shootings took place are closed, but for those working elsewhere in the building, there was an eerie feeling upon their return.
"As CBS 2’s Sylvia Gomez reports, on Friday, the squeal of sirens through the Loop was a sound that could only mean something horrible. The gunman opened fire on people whose only crime seemed to be standing in the wrong place. When the dust settled, four were dead, including gunman Joe Jackson, who truly believed he had reason to snap.
"Offsite grief counseling was underway Monday for those who worked in the law offices where the shootings took place – Woods, Phillips, Katz, Clark & Mortimer, on the 38th floor of the Citicorp Building, 500 W. Madison St. The offices are to reopen on Tuesday.
[snip]
"The only surviving victim was paralegal Ruth Zak Lieb, who was hit in the foot by gunfire and was recovering Monday morning."